Outdoor Robot Load-Rate Braking for Obstacle Contact Detection

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Solution Overview

Problem

Outdoor robots, such as robotic lawnmowers, pose a risk of harm to organisms when they come into contact with high-speed execution apparatuses, necessitating a method to accurately detect obstacles and prevent harm.

Innovation Solution

A control method for outdoor robots that monitors load parameters, such as rotational speed, current, or torque of the execution motor, and brakes the apparatus when a significant change rate exceeds a preset threshold, indicating potential contact with an obstacle, thereby reducing the risk of harm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the execution apparatus runs at high speed to perform work tasks efficiently, then productivity is improved, but the risk of harm to organisms increases

Engineering Contradiction:
Improvework task efficiencyVSAvoidharm to organism
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The control method performs preliminary detection by monitoring load parameters before the execution apparatus can cause harm. The system continuously monitors the execution motor's load parameters and detects abnormal changes that indicate potential contact with organisms, enabling preventive action before significant harm occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback control by continuously monitoring load parameters of the execution motor and using this information to control the execution apparatus. When the load parameter change rate exceeds the threshold, the system provides feedback to brake the execution apparatus, creating a closed-loop safety mechanism that balances productivity and safety.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the load parameter threshold is set low for high sensitivity detection, then measurement precision is improved, but false alarms increase reducing productivity

Engineering Contradiction:
Improveobstacle detection accuracyVSAvoidwork task continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system changes the detection parameter from absolute load value to load parameter change rate. This transformation allows the system to detect obstacles based on the rate of change rather than fixed thresholds, improving detection precision while reducing false alarms caused by normal operational variations in load.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The threshold is made dynamic by using the change rate of load parameters rather than a fixed value. The system adapts to normal operational variations by monitoring how quickly the load changes, allowing flexible detection that maintains high precision without excessive false alarms that would disrupt productivity.

Inventive Principle:
Principle #15Dynamics

3Loss of time

If the load parameter changes rapidly indicating obstacle contact, then detection speed is improved, but the execution apparatus may already have caused harm

Engineering Contradiction:
Improvedetection response timeVSAvoidharm to organism
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection by monitoring load parameters continuously before significant harm occurs. By detecting abnormal change rates in real-time, the system enables preventive braking action before the execution apparatus can cause serious injury, reducing both detection response time and potential harm.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

When an obstacle is detected through rapid load parameter changes, the system rushes to brake the execution apparatus immediately. This rapid response skips the delay of additional confirmation steps, accepting the risk of brief false positives to ensure that if real contact occurred, harm is minimized through immediate action.

Inventive Principle:
Principle #21Skipping (Rushing through)

Data Source

PatentEP4030256B1Outdoor robot and control method therefor
Publication Date: 2024.07.31 POSITEC POWER TOOLS (SUZHOU) CO LTD
  • EP4030256B1 patent drawingFigure 1
  • EP4030256B1 patent drawingFigure 2
  • EP4030256B1 patent drawingFigure 3

AI summary

The present invention provides a control method of an outdoor robot. The outdoor robot includes an execution apparatus and an execution motor for driving the execution apparatus to perform a work task. The control method includes: obtaining a load parameter of the execution motor during running of the outdoor robot; calculating a change rate parameter of a load; and when it is determined that the change rate parameter of the load represents that the load increases and the change rate parameter of the load exceeds a preset threshold range, braking running of the execution apparatus. The control method can detect in time and accurately whether the execution apparatus touches an obstacle such as an organism, and control running of the execution apparatus in time when touching an obstacle, so that the accuracy of detecting an obstacle can be improved, thereby improving the safety and working efficiency of an outdoor robot.